Thermostatic choke valve



Oct. 5, 1965 P. R. HUNTETAL 3,210,004

THERMOSTA'I'IC CHOKE VALVE Filed Dec. 26, 1962 INVENTORS. 401. 16 4 0?gx/wrze 0 5 /5 W,mym

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United States Patent 3,210,094 THERMOSTA'IIC CHOKE VALVE Paul 1%. Hunt,Lindenhurst, and Chester Du Rois, Zion,

Ill., assignors to Qutboard Marine Corporation, Waukegan, Ill., acorporation of Delaware Filed Doc. 26, 1962, Ser. No. 247,253 14 Claims.(Cl. 236101) The invention relates generally to chokes such as areassociated with carburetors or other combustion air-intake arrangementsfor internal combustion engines. More specifically, the inventionrelates to automatic chokes including temperature responsive means forproviding a variably controlled air flow so as to obtain a variablyenriched fuel-air mixture for engine starting and operating.

For various reasons including, for instance, a sticky choke shaft,damage to the temperature responsive automatic operating means, orfaulty delivery of heat to the temperature responsive means, theoperation of an automatic choke may become either partially or whollyunreliable or ineffective.

The invention provides means for manually overriding the automaticoperation of the choke, preferably by means for impositively orresiliently closing the choke and for positively opening the choke. Moreparticularly, in one embodiment of the invention, the overridingpositive and impositive means are both mounted on a single member whichis shiftable from an automatic setting to a first or closed positionremoved from said automatic setting and to a second or open positionremote from the automatic setting. In said one embodiment, the automatictemperature responsive means also is mounted on the shiftable member.

Other objects and advantages of the invention will become known byreference to the following description and the accompanying drawings ofone embodiment of the invention.

In the drawings:

FIGURE 1 is an elevational view partially in section of a choke 11 inaccordance with the invention;

FIGURE 2 is a plan view taken generally along line 2-2 of FIGURE 1;

FIGURE 3 is a view taken generally along line 3-3 of FIGURE 1, showingthe choke in its automatic control setting and with the choke valvemember closed;

FIGURE 4 is a view similar to FIGURES 2 and 3, showing the choke in itsmanually closed settitng;

FIGURE 5 is a view similar to FIGURES 2, 3, and 4, showing the choke inits manually open setting; and

FIGURE 6 is a perspective view showing the mounting of an automaticchoke, such as disclosed herein, on an internal combustion engine.

As shown in the drawings, the choke 11 comprises, in part, a frame orelement 13 including an air or gas passage 14, and a shaft 15 extendingacross the passage 14 and carrying a valve member or plate 17. The shaft15 is rotatably journaled by the frame 13 for variably locating thevalve member 17 between a substantially open position, shown in outlinein FIGURE 5, wherein the valve member 17 lies substantially in a planeextending axially of the air passage 14 and a closed position, shown inoutline in FIGURE 4, wherein the valve member 17 extends across the airpassage 14 in generally blocking relation thereto at an angle of about75 degrees relative to its open position. v

The frame 13 also includes or has mounted thereon a housing or chamber19 which contains an operating mechanism 21 connected to the shaft 15.Although various configurations can be employed, the housing 19 isgenerally cup shaped and is closed by a cap or cover 23 which isangularly shiftable around the mouth of the "ice housing 19 and isconnected to a handle 25 to facilitate such angular shifting.

More specifically, the cap 23 is retained on the housing 19 by aretainer ring 27 which can be secured to the housing 19 by suitablemeans, as for example, a plurality of screws 29. Notwithstanding theangular shiftability of the cap 23 to the housing 19, the cap 23 issealed to the housing 19 and friction is reduced by means of a pair ofgaskets 31 and 33 respectively interposed between the retaining ring 27and the cap 23 and between the cap 23 and the housing 19. The cap 23 andits attached handle 25 are shiftable relative to, and between, manuallyclosed and manually open positions located approximately 180 degreesapart and shown respectively in FIGURES 4 and 5, and relative to anintermediate automatic position located midway between the open andclosed positions, as shown in FIGURES 2 and 3.

Passing through the cap 23 and through a hub 35 projecting from theundersurface of the cap 23 is a stud 37 which is angularly shiftableabout its own axis relative to the cap 23 and which extends into thehousing 19 in generally axial alignment with the shaft 15. Carried bythe stud 37 is a temperature sensitive or responsive means in the formof a bimetallic element or coil 39 having an outer free end which isindicated at 41 and which is reversely curved or hooked. The outerhooked end 41 of the bimetallic coil 39 is located for engagement withan arm 43 which extends in parallel relation to the axes of the stud 37and shaft 15 and which constitutes one part of a right angle leg orbracket 45 fixed to the end of the shaft 15 extending in the housing 19.

In order to adjust the choke, means are provided for varying therelation of the bimetallic coil 39 to the cap 23. In the specificallydisclosed construction, such means take the form of an arrangementincluding a plate 47 which is fixed to the outer end of the stud 37 andwhich is angularly positionable on the top surface of the cap 23. Theplate 47 can be fixed in any desired position of angular relation to thecap 23 by means including an arcuate cut out 48 in the plate 47 and ascrew 49 which connects the handle 25 to the cap 23 and which passesthrough the cut out 48. By loosening the screw 49, the plate 47 and theconnected stud 37, together with the bimetallic coil 39, can beangularly shifted relative to the cap 23. When a desired adjustment isobtained, the screw 49 is then tightened to prevent further relativeangular movement between the plate 47 and the cap 23.

When the bimetallic coil 39 is cold, and when the cap 23 is in automaticposition, as shown in FIGURES 2 and 3, the hooked outer end 41 of thebimetallic coil 39 is positioned to engage the arm 43 to locate thevalve member 17 in its closed position. Heating of the bimetallic coil39 causes its hooked outer end 41 to rotate in a counterclockwisedirection, as shown in FIGURE 3, permitting the arm 43 to move, underthe influence of gas flow within the air passage 13 from the closedposition, shown in full lines in FIGURE 3, to the open position shown indotted outline in FIGURE 3. Should the bimetallic coil 39 again cool,the hooked end 41 will rotate in a clockwise direction toward theclosed, full line position shown in FIGURE 3, thereby proportionatelyrestricting the amount of gas flow permitted by the valve member 17 asthe hooked end of the bimetallic coil travels from its open position toits closed position.

The air passageway 14 can be manually closed, when the bimetallic coilis heated, by rotating the cap 23 in a clockwise direction as seen inFIGURES 2 through 5, through an angle of about degrees from theautomatic setting to the position shown in FIGURE 4. Counter-clockwisemovement of the cap 23 can be limited to about 90 degrees by suitablemeans, such as by en- 3 gagement of a stop 51 on the top surface of thecap 23 with a radially inwardly extending detent or lug 53 projectingfrom the retainer ring 27.

Such movement of the cap to its manually closed position rotates thestud 37 and the connected bimetallic coil 39 through a correspondingangle. In the event the bimetallic coil 39 is cooled with its hooked endlocated as shown in full lines in FIGURE 3, such movement will effectresilient displacement of the bimetallic coil 39 from its normalrelation to the stud 37. In the event the bimetallic coil 39 is heatedand the valve member 17 is at least partially open, the hooked end 41will be rotated so as to engage and at least partially advance the arm43 toward its closed position.

However, in the event that the linkage between the cap 23 and the shaftis interrupted, as by breaking of the bimetallic coil 39 or by looseningof the screw 49, thereby permitting shifting of the plate 4-7 relativeto the cap 23, movement of the arm 43 to its valve member closingposition is assured by biasing means which, in the specificallydisclosed construction, takes the form of a spring 55 carried by the cap23.

More specifically, the spring 55 is formed with at least one coilencircling the hub and is fixedly connected, by suitable means indicatedat 56 in FIGURE 3, at the end of one leg 57 to the cap 23. The other leg59 projects into a position for engagement with the arm 43 to displacethe arm to its valve member closing position in response to rotation ofthe cap 23 to its manually closed position. As the full range ofmovement of the arm 43 between its open and its closed positions isthrough an arc of about 75 degrees, movement of the spring through anangle of 90 degrees, by reason of like angular shifting of the cap 23 toits manually closed position, serves both to engage the arm 43 by thespring in response to initial shifting of the cap 23 and to locate theend or leg 59 of the spring 55 in a tensioned condition afterdisplacement of the arm 43 to its valve member closing position.Consequently, maintenance of the valve member 17 in closing relation tothe air passage 14 is assured when the cap 23 is in its manually closedposition.

Notwithstanding the above, when the cap 23 is in its manually closedposition with the valve member 17 retained in closing relation to theair passage 14 by the spring 55 and by the bimetallic coil 39, thearrangement permits breathin through the air passage 14 by reason ofvalve member action against the torque loading of the bimetallic coil 39and spring 55 in response to a sufiicient draft or vacuum in the airpassage 14. Such breathing provides the operator with time to reset thecap to its automatic position before the engine dies because of anexcessiveiy rich mixture.

When a lean mixture is required for starting, the cap 23 can be rotatedto the manually open position shown in FIGURE 5. Such action can occurwhen the bimetallic coil 39 is cold and in the position shown in FIGURE3. Because of the absence of fixed engagement between the bimetalliccoil 39 and the arm 43, mere rotation of the bimetallic coil 39 in acounterclockwise direction as seen in FIGURE 5, accompanying likerotative movement of the cap 23, will not effect positive movement ofthe valve member 17 from its closed position in the absence of asufficient pressure differential or draft across the opposite faces ofthe valve member. Accordingly, means in the form of a lug 61 is providedon the undersurface of the cap 23, which lug projects for engagementwith the arm 43 in response to movement of the cap through an arc ofabout 90 degrees from the automatic position. As only about 75 degreesof rotation is required to displace the arm 43 from its valve memberclosing position to its valve member opening position, the initial 15degrees of movement of the cap 23 permits disengagement of the hookedend 41 of the bimetallic coil 39 from the arm 43 prior to engagement ofthe lug 61 with the arm. Thus, movement of the arm 43 from its valvemember closing position to its valve member opening position occursentirely without any load on the bimetallic element.

Upon return of the cap 23 to its automatic position, the hooked end 41of the bimetallic coil 39 will engage the arm d3 for movement of the armbetween its valve member opening position and its valve member closingposition in accordance With the extent to which the bi metallic coil 39is heated. Movement of the cap 23 through the automatic position to themanually closed position will effect displacement of the arm 43 to itsvalve member closing position, notwithstanding any heated condition ofthe bimetallic coil 39 by action of the spring 55.

Various arrangements can be used to effect heating of the bimetalliccoil 3% in response to heating of the engine. For instance, the housing19 could be arranged so that it is mounted on an engine block orotherwise conveniently located so as to be heated by conduction. InFIGURE 6, a choke 111 embodying various of the features of the inventionis shown mounted on the exhaust manifold of an engine 105 so as toreceive heat from the engine incident to operation thereof. In addition,or alternatively, the heat source for the bimetallic coil 33 can takethe form of an air flow which has been previously heated by the exhaustof the engine and which is drawn into the housing by intake manifoldvacuum pressure, as for instance, through a conduit 65 such as shown inFIGURE 5.

While the discussed arrangement has included a handle 25 attached to thecap 23 for angularly shifting the cap, various arrangements such ascable or other means can be employed for angularly shifting the cap froma remote point.

Various of the features of the invention are set forth in the followingclaims.

What is claimed is:

1. A choke for controlling gas fiow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for rotative movement about an axis transverse to said gaspassage between a first position closing said passage and a secondposition permitting relatively free flow through said passage,temperature responsive means free of fixed connection with said valvemember and operative to connect with said valve member for controllingthe movement of said valve member between said first position and saidsecond position, and manually operative means for locating said valvemember relative to said first and second positions notwithstanding theaction of said temperature responsive means.

2. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for rotative movement abount an axis transverse to said gaspassage between a first position closing said passage and a secondposition permitting relatively unobstructed flow through said passage,temperature responsive means free of fixed connection with said valvemember and operative to connect with said valve member for displacingsaid valve member from said second position to said first position inresponse to a change in one direction of the temperature of saidtemperature responsive means and for permitting movement of said valvemember from said second position to said first position in response to achange in the other direction of the temperature of said temperatureresponsive means, and manually operative means for locating said valvemember relative to said first and second positions notwithstanding theac tion of said temperature responsive means.

3. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for displacement between a first position closing said passageand a second position permitting relatively unobstructed fiow throughsaid passage, means connected to said valve member for displacing saidvalve member between said first and second positions, temperatureresponsive means having a portion disposed for engagement with saidvalve member displacing means to displace said valve member to its firstposition in response to cooling of said temperature responsive meansfrom a relatively heated condition and for permitting movement of saidvalve member from its first position toward its second position inresponse to heating of said temperature responsive means from arelatively cool condition, manually shiftabtle resilient means connectedto said gas passage defining means for engaging said valve memberdisplacing means to locate said valve member in said first positionnotwithstanding the action of said temperature responsive means, andmanually shiftable rigid means connected to said gas passage definingmeans for engagement with said valve member displacing means to locatesaid valve member in its second position notwithstanding the action ofsaid temperature responsive means.

4. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for displacement between a first position closing said passageand a second position permitting relatively unobstructed flow throughsaid passage, means for displacing said valve member between said firstand second positions including a crank arm connected to said valvemember and movable between a first position locating said valve memberin its first position and a second position locating said valve memberin its second position, means manually shiftable for movement inopposite directions from a predetermined position, resilient meanscarried by said shiftable means for engaging said crank arm to locatesaid crank arm in its first position in response to movement of saidshiftable means in one direction from said predetermined position, fixedmeans on said shiftable means in position for engagement with said crankarm to locate said crank arm in its second position in response tomovement of said shiftable means from said predetermined position in adirection opposite from said one direction, and temperature responsivemeans carried by said shiftable means and having a portion disposed,when said shiftable means is in said predetermined position, formovement in the path of movement of said crank arm for engagement withsaid crank arm to displace said crank arm to its first position inresponse to cooling of said temperature responsive means from arelatively heated condition and for permitting movement of said crankarm from its first position toward its second position in response toheating of said temperature responsive means from a relatively coolcondition.

5. A choke in accordance with claim 4 including means for limitingmovement of said manually shiftable means in said one direction tocontrol the stress in said resilient means.

6. A choke in accordance with claim 4 wherein said temperatureresponsive means is carried on said manually shiftable means by meansfor selectively shifting the disposition of said temperature responsivemeans relative to said manually shiftable means.

7. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for angular displacement between a first position closing saidpassage and a second position permitting relatively unobstructed flowthrough said passage, means for displacing said valve member betweensaid first and second positions including a crank arm connected to saidvalve member and movable between a first position locating said valvemember in its first position and a second position locating said valvemember in its second position, means manually shiftable for movementthrough a first angular distance greater than the angular distancebetween said first and second positions of said valve member between afirst closed position and a second automatic position and for movementthrough a second angular distance greater than the angular distancebetween said first and second positions of said valve member betweensaid automatic position and a third open position, resilient meanscarried by said shiftable means for engaging said crank arm to locatesaid crank arm in its first position in response to movement of saidshiftable means from its automatic position to its closed position onlyafter an initial range of movement from said automatic position lessthan the difference between the range of angular movement of said valvemember and the range of angular movement of said shiftable means betweenits automatic and its closed positions, fixed means on said shiftablemeans in position for engagement with said cank arm to locate said crankarm in its second position in response to movement of said shiftablemeans from its automatic position to its open position only after aninitial range of limited movement from said automatic position,temperature responsive means carried by said shiftable means and havinga portion disposed, when said shiftable member is in its automaticposition, for movement in the path of movement of said crank arm forengagement with said crank arm to displace said crank arm to its firstposition in response to cooling of said temperature re- ,sponsive meansfrom a relatively heated condition and so as to permit movement of saidcrank arm from its first position toward its second position in responseto heating of said temperature responsive means from a relatively coolcondition.

8. A choke for controlling gas flow comprising a frame including meansdefining a gas passage, a cup-shaped housing on said frame, a shaftextending across said gas passage and into said housing, a valve memberon said shaft in said gas passage, means mounting said shaft for angulardisplacement of said valve member between a first position closing saidpassage and a second position permitting relatively free flow throughsaid passage, a crank arm in said housing connected to said shaft andmovable between a first position locating said valve member in its firstposition and a second position locating said valve member in its secondposition, a cover, means mounting said cover on said housing for manualangular shifting relative to said housing in opposite directions from apredetermined position, a spring carried by said cover in said housingand including an end displaceable in the path of movement of said crankarm for engaging said crank arm to locate said crank arm in its firstposition in response to movement of said cover in one direction fromsaid predetermined position, a lug on said cover within said housing inposition for engagement with said crank arm to locate said crank arm inits second position in response to movement of said cover from saidpredetermined position in a direction opposite from said one direction,and a bimetallic coil carried by said cover within said housing andhaving a hooked end portion disposed, when said cover is in saidpredetermined position, for movement in the path of movement of saidcrank arm so as to engage said crank arm to displace said crank arm toits first position in response to cooling of said temperature responsivemeans from a relatively heated condition and so as to permit movement ofsaid crank arm from its first position toward its second position inresponse to heating of said temperature responsive means from arelatively cool condition.

9. A choke in accordance with claim 8 wherein said cover is angularlyshiftable about an axis in alignment with the rotational axis of saidshaft.

10. A choke in accordance with claim 8 including means for limitingmovement of said cover in said one direction to control the stress insaid spring.

11. A choke in accordance with claim 8 wherein said bimetallic coil iscarried on said cover by means for selectively shifting the dispositionof said bimetallic coil relative to said cover.

12. A choke in accordance with claim 8 in combination with an internalcombustion engine and means munting said choke on said engine inposition for heating said housing in response to operation of saidengine.

13. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for rotative movement about an axis transverse to said passagebetween a first position closing said passage and a second positionpermitting relatively free flow through said passage, temperatureresponsive means for controlling the movement of said valve memberbetween said first position and said second position, and manuallyoperative means free of fixed connection with said valve member andoperative to connect with said valve member for locating said valvemember relative to said first and second positions notwithstanding theaction of said temperature responsive means.

14. A choke for controlling gas flow comprising means defining a gaspassage, a valve member, means mounting said valve member in said gaspassage for rotative movement about an axis transverse to said passagebetween a first position closing said passage and a second positionpermitting relatively unobstructed flow through said pas sage,temperature responsive means engageable with said valve member fordisplacing said valve member from said second position to said firstposition in response to a change in one direction of the temperature ofsaid temperature responsive means and for permitting movement of saidvalve member from said second position to said first position. inresponse to a change in the other direction of the temperature of saidtemperature responsive means, and manually operative means free of fixedconnection with said valve member and operative to connect with saidvalve member for locating said valve member relative to said first andsecond positions notwithstanding the action of said temperatureresponsive means.

References Cited by the Examiner UNITED STATES PATENTS 1,530,850 3/25Partlow 236-102 1,849,906 3/32 Carson 23642 2,019,589 11/35 Weber 23610l2,180,800 11/39 Cyr 236-101 X 2,351,190 6/44 Carlson 236-92 2,571,60210/51 Neuser 236101 2,646,933 7/55 Boyce 236-101 EDWARD J. MICHAEL,Primary Examiner.

ALDEN D. STEWART, Examiner.

1. A CHOKE FOR CONTROLLING GAS FLOW COMPRISING MEANS DEFINING A GASPASSAGE, A VALVE MEMBER, MEANS MOUNTING SAID VALVE MEMBER IN SAID GASPASSAGE FOR ROTATIVE MOVEMENT ABOUT AN AXIS TRANSVERSE TO SAID GASPASSAGE BETWEEN A FIRST POSITION CLOSING SAID PASSAGE AND A SECONDPOSITION PERMITTING RELATIVELY FREE FLOW THROUGH SAID PASSAGE,TEMPERATURE RESPONSIVE MEANS FREE OF FIXED CONNECTION WITH SAID VALVEMEMBER AND OPERATIVE TO CONNECT WITH SAID VALVE MEMBER FOR CONTROLLINGTHE MOVEMENT OF SAID VALVE MEMBER BETWEEN SAID FIRST POSITION AND SAIDSECOND POSITION, AND MANUALLY OPERATIVE MEANS FOR LOCATING SAID VALVEMEMBER RELATIVE TO SAID FIRST AND SECOND POSITIONS NOTWITHSTANDING THEACTION OF SAID TEMPERATURE RESPONSIVE MEANS.